Film-type pressure sensors are used in a wide range of applications, e.g. as input devices for human-machine or human-computer interaction, or for vehicle seat occupancy sensing and/or classification, and the like.
Document U.S. 2010/0063779 discloses a shoe with an integrated film-type pressure sensor. The sensor system collects performance data that are transferred for further use via a communication port. The shoe contains a force sensor arranged in the sole structure for measuring, in a plurality of areas, pressure (force) exerted by the wearer's foot on the sole structure, and an electronic module configured to gather data from the sensors. The module is configured for transmitting the data to an external device for further processing. In one of the embodiments disclosed in U.S. 2010/0063779, the pressure sensor comprises four elongated pressure-sensing cells, each of which contains a first and a second electrode as well as a force-sensitive resistive material disposed between the electrodes to electrically connect the electrodes together. When pressure is applied to the force-sensitive material, the resistivity of the latter changes and the resulting change in resistance is detected by the electronic module.
In most of today's applications, each pressure sensor comprises its dedicated electronic control module that evaluates the pressure exerted on the one or more pressure-sensing cells. This will not necessarily be the case in the future. Indeed, U.S. 2010/0063779 already mentions that the electronic control module may be removable from the article of footwear at the option of the user. The user may replace it with another, possibly differently configured, module. It is also possible that the user possesses only one pair of electronic control modules, which he uses with different pairs of shoes. Of course, such interchangeability requires some standardization effort. For instance, the electrical interfaces of different film-type pressure sensors have to be compatible with different electronic control modules. However, the different film-type pressure sensors will not be equal in all respects. There could be differences as regards the number, the shape, the position etc. of the pressure-sensing cells, the materials used (and thus the response characteristics) etc. In order for the electronic control module to take such differences into account, the user may thus be required to adjust some settings of the electronic control module when uses it with another pressure sensor. That complicates the exchange procedure and is a potential source of avoidable handling errors.